The phrase to have swallowed a, or the, dictionary means:
– to use long or obscure words in speech, especially excessively or unnecessarily;
– to speak grandiloquently or bombastically.
With reference to the Latin dictionary compiled by Ambrosio Calepino *, an early occurrence of the phrase is found in The Laudable Faculty of Lying, in Citt and Bumpkin, or, A Learned Discourse upon Swearing and Lying, and other Laudable Qualities tending to a Thorow Reformation. The Second Part (London: Printed for Henry Brome […], 1680), by the English author and press censor Roger L’Estrange (1616-1704):
Tru. Has he any Languages too?
Citt. If you had him but one half-hour upon the Talking-Pin,
you’d swear that he had swallow’d Calepines Dictionary whole, and
spew’d it up again.
* The Augustine friar Ambrosio Calepino (Latin Ambrosius Calepinus – ca 1440-1510), of Calepio in Italy, was the author of a famous Latin dictionary, first published in 1502, which in its many editions was the 16th-century Latin dictionary of reference.
These are, in chronological order, the earliest occurrences of the phrase to have swallowed a, or the, dictionary that I have found:
1-: From a letter published in the Northern Whig (Hudson, New York) of Tuesday 10th October 1815—the author of the letter was reacting to an article in which one General Haight had criticised him:
I congratulate the General on having such a quill-valiant Aid. Body o’me, how big he talks! What hard words he uses, too! The fellow must certainly have swallowed a Dictionary!
2-: From a letter published in The Tyne Mercury; or, Northumberland, Durham, and Cumberland Gazette (Newcastle upon Tyne, Northumberland, England) of Tuesday 15th October 1822:
I wish it to be understood, that I mean by an amateur, […] a fellow who, not having the slightest practical knowledge of the arts, pesters the ears of all he meets (like a gadfly in summer) with nonsensical jargon which almost puzzles his own silly tongue to deliver, and tremendously perplexes every body else to understand […]. Somebody observed of a man who pretended to be full of learning, that he talked as if he had swallowed a dictionary. These amateurs talk as if they had swallowed a painter, palette, pencils, “pots and all,” and were disgorging him and his cargo upon the unlucky person of every passenger in the street.
3-: From the Middlesex Gazette (Middletown, Connecticut) of Wednesday 8th August 1827:
The Pennsylvania bacchanalians are proficients [sic] in the art of toast-making. Hear what a Solomon of Reading says:
“The Fair Sex. Man’s consolation in the hour of anxiety, and decoration of the human race—whose smiles are as luscious as nectar, and emphasis melodiously bewitching as the harmony of Orpheus—may chastity and veracity be their ocular demonstration; and may they never be assumptioned egress by the pomp of glittering superficialities!!”
He must have swallowed a dictionary without chewing. It is rather more unintelligible than the following. The scinctillations [sic] of wit, and the coruscations of genius, elicited from the pericranium of this man, by the action of aqua vitæ on the contents of the pia mater are superlatively exquisite.
4-: From The Collegians (London: Saunders and Otley, 1829), by the Irish novelist, playwright and poet Gerald Griffin (1803-1840):
“Whatever way Saint Sweeten’s day is, its [sic] the same way for forty days after. You don’t b’lieve that sir, now?”
“Indeed, I am rather doubtful.”
“See that why! Why then I seen a schoolmaster westwards that had as much Latin and English as if he had swallowed a dictionary, an’ he’d outface the world that it was as true as you’re going the road this minute.”
5-: From “Hard to please”, about one Simon Squizzle Jun., published in The Burlington Free Press (Burlington, Vermont) of Friday 23rd July 1830:
It’s true Simon […] you can make a speech of words, words, words, of wondrous length and thundering sound as if you had swallowed a dictionary and taken a cathartic to carry it off. But what does all this amount to? a parrot could do as much and the hearers would be equally edified, equally instructed and convinced.
6-: From the Newburyport Herald (Newburyport, Massachusetts) of Tuesday 14th September 1830:
As old Bill H —— was the other day descanting on some occurrence, in an abstruse dialect, a friend ventured to remark, ‘Why Mr. H. I guess you have swallowed a Dictionary.’—‘You have nearly hit it,’ was the reply, ‘for I have just finished a dinner of sounds and tongues.*’
* This luscious dish, it will be remembered, is a favorite article of diet in sea ports connected with the cod-fishery.